'use strict';

// module to handle cookies

const urllib = require('url');

const SESSION_TIMEOUT = 1800; // 30 min

/**
 * Creates a biskviit cookie jar for managing cookie values in memory
 *
 * @constructor
 * @param {Object} [options] Optional options object
 */
class Cookies {
  constructor(options) {
    this.options = options || {};
    this.cookies = [];
  }

  /**
   * Stores a cookie string to the cookie storage
   *
   * @param {String} cookieStr Value from the 'Set-Cookie:' header
   * @param {String} url Current URL
   */
  set(cookieStr, url) {
    let urlparts = urllib.parse(url || '');
    let cookie = this.parse(cookieStr);
    let domain;

    if (cookie.domain) {
      domain = cookie.domain.replace(/^\./, '');

      // do not allow cross origin cookies
      if (
        // can't be valid if the requested domain is shorter than current hostname
        urlparts.hostname.length < domain.length ||
        // prefix domains with dot to be sure that partial matches are not used
        ('.' + urlparts.hostname).substr(-domain.length + 1) !== '.' + domain
      ) {
        cookie.domain = urlparts.hostname;
      }
    } else {
      cookie.domain = urlparts.hostname;
    }

    if (!cookie.path) {
      cookie.path = this.getPath(urlparts.pathname);
    }

    // if no expire date, then use sessionTimeout value
    if (!cookie.expires) {
      cookie.expires = new Date(Date.now() + (Number(this.options.sessionTimeout || SESSION_TIMEOUT) || SESSION_TIMEOUT) * 1000);
    }

    return this.add(cookie);
  }

  /**
   * Returns cookie string for the 'Cookie:' header.
   *
   * @param {String} url URL to check for
   * @returns {String} Cookie header or empty string if no matches were found
   */
  get(url) {
    return this.list(url)
      .map(cookie => cookie.name + '=' + cookie.value)
      .join('; ');
  }

  /**
   * Lists all valied cookie objects for the specified URL
   *
   * @param {String} url URL to check for
   * @returns {Array} An array of cookie objects
   */
  list(url) {
    let result = [];
    let i;
    let cookie;

    for (i = this.cookies.length - 1; i >= 0; i--) {
      cookie = this.cookies[i];

      if (this.isExpired(cookie)) {
        this.cookies.splice(i, i);
        continue;
      }

      if (this.match(cookie, url)) {
        result.unshift(cookie);
      }
    }

    return result;
  }

  /**
   * Parses cookie string from the 'Set-Cookie:' header
   *
   * @param {String} cookieStr String from the 'Set-Cookie:' header
   * @returns {Object} Cookie object
   */
  parse(cookieStr) {
    let cookie = {};

    (cookieStr || '')
      .toString()
      .split(';')
      .forEach(cookiePart => {
        let valueParts = cookiePart.split('=');
        let key = valueParts
          .shift()
          .trim()
          .toLowerCase();
        let value = valueParts.join('=').trim();
        let domain;

        if (!key) {
          // skip empty parts
          return;
        }

        switch (key) {
          case 'expires':
            value = new Date(value);
            // ignore date if can not parse it
            if (value.toString() !== 'Invalid Date') {
              cookie.expires = value;
            }
            break;

          case 'path':
            cookie.path = value;
            break;

          case 'domain':
            domain = value.toLowerCase();
            if (domain.length && domain.charAt(0) !== '.') {
              domain = '.' + domain; // ensure preceeding dot for user set domains
            }
            cookie.domain = domain;
            break;

          case 'max-age':
            cookie.expires = new Date(Date.now() + (Number(value) || 0) * 1000);
            break;

          case 'secure':
            cookie.secure = true;
            break;

          case 'httponly':
            cookie.httponly = true;
            break;

          default:
            if (!cookie.name) {
              cookie.name = key;
              cookie.value = value;
            }
        }
      });

    return cookie;
  }

  /**
   * Checks if a cookie object is valid for a specified URL
   *
   * @param {Object} cookie Cookie object
   * @param {String} url URL to check for
   * @returns {Boolean} true if cookie is valid for specifiec URL
   */
  match(cookie, url) {
    let urlparts = urllib.parse(url || '');

    // check if hostname matches
    // .foo.com also matches subdomains, foo.com does not
    if (
      urlparts.hostname !== cookie.domain &&
      (cookie.domain.charAt(0) !== '.' || ('.' + urlparts.hostname).substr(-cookie.domain.length) !== cookie.domain)
    ) {
      return false;
    }

    // check if path matches
    let path = this.getPath(urlparts.pathname);
    if (path.substr(0, cookie.path.length) !== cookie.path) {
      return false;
    }

    // check secure argument
    if (cookie.secure && urlparts.protocol !== 'https:') {
      return false;
    }

    return true;
  }

  /**
   * Adds (or updates/removes if needed) a cookie object to the cookie storage
   *
   * @param {Object} cookie Cookie value to be stored
   */
  add(cookie) {
    let i;
    let len;

    // nothing to do here
    if (!cookie || !cookie.name) {
      return false;
    }

    // overwrite if has same params
    for (i = 0, len = this.cookies.length; i < len; i++) {
      if (this.compare(this.cookies[i], cookie)) {
        // check if the cookie needs to be removed instead
        if (this.isExpired(cookie)) {
          this.cookies.splice(i, 1); // remove expired/unset cookie
          return false;
        }

        this.cookies[i] = cookie;
        return true;
      }
    }

    // add as new if not already expired
    if (!this.isExpired(cookie)) {
      this.cookies.push(cookie);
    }

    return true;
  }

  /**
   * Checks if two cookie objects are the same
   *
   * @param {Object} a Cookie to check against
   * @param {Object} b Cookie to check against
   * @returns {Boolean} True, if the cookies are the same
   */
  compare(a, b) {
    return a.name === b.name && a.path === b.path && a.domain === b.domain && a.secure === b.secure && a.httponly === a.httponly;
  }

  /**
   * Checks if a cookie is expired
   *
   * @param {Object} cookie Cookie object to check against
   * @returns {Boolean} True, if the cookie is expired
   */
  isExpired(cookie) {
    return (cookie.expires && cookie.expires < new Date()) || !cookie.value;
  }

  /**
   * Returns normalized cookie path for an URL path argument
   *
   * @param {String} pathname
   * @returns {String} Normalized path
   */
  getPath(pathname) {
    let path = (pathname || '/').split('/');
    path.pop(); // remove filename part
    path = path.join('/').trim();

    // ensure path prefix /
    if (path.charAt(0) !== '/') {
      path = '/' + path;
    }

    // ensure path suffix /
    if (path.substr(-1) !== '/') {
      path += '/';
    }

    return path;
  }
}

module.exports = Cookies;
